Split-Flap Display Nearly 3 Years in the Making
If you want a clock, even one with a mechanical split-flap display, they’re available at the store or online for under $20. If you want something that you can control with letters added in, displays of this type are quite difficult to obtain. This didn’t stop hacker “scottbez1,” who constructed his own split-flap display that cranks out letters, numbers, and even some punctuation.
The project was designed using the OPENSCAD package, and electronics plug into an Arduino Uno board as a shield. As needed, several character modules can be daisy-chained together and used to display simple words. Each unit uses its own stepper motor to flip through characters, and an IR sensor notes the position of a hole on one of the driving gears, allowing it to align itself as necessary.
While the display works quite well now, the build was fraught with challenges that needed to be overcome, such as the fact that the motors chosen come in slightly different gear ratios with no discernible markings to tell between the two. Even cutting the ID card material used for the flaps required some creativity in the form of a custom jig. You can see it clicking through a series of letters in the video below, and if you’d like to build your own, Arduino code and other build details are available on GitHub.